Stucco Repair 101

Dryvit Stucco Installation is a straightforward procedure that brings most plaster surfaces back to their original condition. Inspect the stucco for cracks, holes, stains, mold or moss growth, soft spots, and impact damage.

Cover windows, doors, and other adjacent surfaces with plastic sheeting to avoid accidental splatters of stucco mix or other repair materials.

Stucco is one of the most durable and resilient building materials available, but it isn’t impervious to wear and tear. Cracking is a normal part of the lifespan of stucco and, in general, can be fixed fairly easily. However, the size of the crack and the reasons it formed should determine the approach taken for repair.

The most common type of cracking in stucco is hairline cracks less than 1/8 inch wide. While these cracks don’t necessarily impact the structure of a home, they do create paths for moisture to enter and cause damage like peeling paint, wood rot, mold, swollen drywall, and more. Hairline cracks can be repaired using a caulking material.

Larger cracks (1/4 inch and wider) and holes should be repaired using a premixed stucco patching product. Purchase the product from a local hardware store and follow the package instructions for mixing and application. This is not a job for a do-it-yourselfer but can be handled by a knowledgeable homeowner who understands the process and has the proper tools.

Before applying the patch:

  1. Use a putty knife or scratch awl to clean out loose debris in the cracks.
  2. Fill the cracks with high-quality caulking.
  3. Apply the patching with a rubber float in thin layers until you reach the level of the surrounding stucco.
  4. Use a wire-bristled brush to add texture to the patch to match the existing stucco.

If you’re repairing cracks that are larger than 1/4 inch, it’s best to have a professional assess the area and determine why the stucco cracked to prevent it from happening again in the future. A contractor can also advise on the best repair method for the cracks and help with color matching to ensure the patching looks natural.

In some cases, the cracks may be caused by climbing plants like vines. In this case, it’s important to remove the plants from the wall as soon as they turn yellow or brown and before they break apart in the wind or get blown away. Once the plant is gone, apply a fog coat or similar product to patch the area and blend it with the rest of the stucco.

Stucco is an attractive material for exterior walls. It provides insulation, is fire retardant, reduces outside noise, and lasts for decades when cared for properly. However, if your stucco walls develop holes, it’s important to fix them as soon as possible. Not only are holes unsightly, but they can lead to water damage and other issues. Fortunately, setting them is relatively simple.

Start by using a wire brush to clean the area around the hole. This will help to ensure the new patching materials will bond with the rest of the wall. You can purchase an automotive wire brush from any hardware store to do this task. After you’ve cleaned the surface, blow out the hole to remove any loose debris that could adversely affect the integrity of the patching materials.

The next step is to inspect the holes and determine if they need to be removed entirely or repaired. Loose stucco will bulge and feel spongey to the touch, while intact stucco will have a solid sound when struck. If your stucco is only partially open, you can try to re-attach it with a hammer and cold chisel, being careful not to damage the wood lath supports underneath.

If the holes are large, you may need to create a backing for the new patching material. This can be as simple as a piece of plywood for a single hole, or you may need wood for a larger wall section surrounding the holes. Once the backing is in place, wet the hole’s surface with a sponge for a small hole or a garden hose for a larger area. This will prevent the repair material from drying too quickly.

Once the hole is wet, mix a batch of stucco repair compound according to the instructions on the package. Then, apply the patch to the holes or cracks in the stucco wall with a putty knife or trowel, working the compound into the hole until it is smooth and matches the texture of the surrounding wall.

If you want to refrain from undertaking the project, a siding contractor can provide a professional service. These contractors will take the time to examine your home’s current structure and landscaping to avoid causing any damage during the installation process. They will also work to ensure any underlying issues are addressed before installing your new stucco, ensuring it will look its best for years to come.

Stucco resists mold, rot, and rodents, but it can still suffer damage from direct impacts. Small cracks and bald spots on the exterior are easy to patch with paintable caulk. Still, a good stucco repair professional should be hired for major damage or if the existing structure of your home has been compromised by moisture or critters.

Stuck-on debris like moss and plant growth can be removed with a wire brush or broom. Alternatively, you can use a power washer in a low-pressure setting. It’s important to avoid using too much pressure, as excessive force can cause structural damage to your home. Stucco surfaces should be cleaned at least twice a year to remove dirt buildup in the pores, which can lead to mold and mildew.

If the problem is a crack, widen it with a cold chisel or hand hammer, or rent an electric chipping hammer fitted with a masonry chisel bit. The chisel should not cut through the underlying stucco; fracture it. This allows the underlying wire mesh and building paper to remain undamaged. Pro Tip: When hammering on the surface of the crack, make sure your fracture lines meander; this makes it easier to disguise them with patch stucco later.

Depending on your needs, you may need to replace the metal mesh in the area of the damaged section. If you do, it’s best to use galvanized steel mesh that will withstand the elements. Measure the area that needs to be covered, then cut a piece of new mesh to size with metal snips.

Once the replacement mesh is in place, it’s a good idea to pull back the undamaged house wrap and felt paper to give yourself some room to work. Next, use tin snips to cut away the house wrap and felt around the damaged section of stucco. This should be done as close to the damaged stucco so that if water gets in behind the new tar paper, it will run out and away from the wood framing underneath.

Finally, it’s a good idea to install a weep screed along the base of your stucco wall, especially if you have a high water table or have had problems with standing water. The weep screed is a strip of cement along the bottom of your stucco wall that helps prevent water from pooling and seeping into cracks in the foundation or drywall.

Aside from cracks, a major sign of impending stucco failure is moisture. Moisture leads to mold and mildew, which destroy the underlying structure of your home. It can also cause unsightly stains and discoloration. It’s important to detect and repair water leaks as early as possible so that the damage doesn’t worsen. Look for damp spots around windows and doors, discolored or textured surfaces, peeling paint or wallpaper, and a musty smell indoors.

Leaks are usually caused by improper flashing and sealants rather than by the stucco. The best way to prevent them is to inspect the flashing regularly and replace deteriorated materials.

Check the roof eaves for adequate overhangs to protect the stucco from direct rainfall, and ensure that the flashing is installed properly at window sills and door heads. A well-installed flashing system includes pan flashing at the sill, Z-flashing with end dams at heads, and a water-resistant barrier on all penetrations into your home’s exterior walls.

Stucco can withstand moisture better than other materials, but even the most durable stucco needs regular maintenance to stay in good condition. It’s important to clean it regularly, at least twice a year, with a pressure washer or hose sprayer. This removes organic material that encourages fungal growth, as well as dirt and dust that can introduce cracks.

A good rule of thumb is to use paintable acrylic caulk to patch any developing fissures. If you notice significant damage or large holes, it’s always best to call a stucco pro.

Before patching, if necessary, use a pry bar or chisel to remove the damaged stucco and underlying lath, and be sure to leave some undamaged stucco in the repair area. Next, score the surface of the remaining stucco and remove any tin snips or house wrap from the area with a hammer or cold chisel. Mist the patch with water before applying the second coat. Wait seven days, then mist again after the patch loses its wet sheen.